Merge branches 'fixes', 'mcpm', 'misc' and 'mmci' into for-next

[karo-tx-linux.git] / arch / arm / kernel / process.c

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index f219703168366f8142321b93750e0027f1e6c6b2..7f1efcd4a6e90ff0350abdfa6f492e60cfbbd028 100644 (file)
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -39,6 +39,7 @@
 #include <asm/thread_notify.h>
 #include <asm/stacktrace.h>
 #include <asm/mach/time.h>
+#include <asm/tls.h>
 
 #ifdef CONFIG_CC_STACKPROTECTOR
 #include <linux/stackprotector.h>
@@ -184,30 +185,61 @@ int __init reboot_setup(char *str)
 
 __setup("reboot=", reboot_setup);
 
+/*
+ * Called by kexec, immediately prior to machine_kexec().
+ *
+ * This must completely disable all secondary CPUs; simply causing those CPUs
+ * to execute e.g. a RAM-based pin loop is not sufficient. This allows the
+ * kexec'd kernel to use any and all RAM as it sees fit, without having to
+ * avoid any code or data used by any SW CPU pin loop. The CPU hotplug
+ * functionality embodied in disable_nonboot_cpus() to achieve this.
+ */
 void machine_shutdown(void)
 {
-#ifdef CONFIG_SMP
-       smp_send_stop();
-#endif
+       disable_nonboot_cpus();
 }
 
+/*
+ * Halting simply requires that the secondary CPUs stop performing any
+ * activity (executing tasks, handling interrupts). smp_send_stop()
+ * achieves this.
+ */
 void machine_halt(void)
 {
-       machine_shutdown();
+       smp_send_stop();
+
        local_irq_disable();
        while (1);
 }
 
+/*
+ * Power-off simply requires that the secondary CPUs stop performing any
+ * activity (executing tasks, handling interrupts). smp_send_stop()
+ * achieves this. When the system power is turned off, it will take all CPUs
+ * with it.
+ */
 void machine_power_off(void)
 {
-       machine_shutdown();
+       smp_send_stop();
+
        if (pm_power_off)
                pm_power_off();
 }
 
+/*
+ * Restart requires that the secondary CPUs stop performing any activity
+ * while the primary CPU resets the system. Systems with a single CPU can
+ * use soft_restart() as their machine descriptor's .restart hook, since that
+ * will cause the only available CPU to reset. Systems with multiple CPUs must
+ * provide a HW restart implementation, to ensure that all CPUs reset at once.
+ * This is required so that any code running after reset on the primary CPU
+ * doesn't have to co-ordinate with other CPUs to ensure they aren't still
+ * executing pre-reset code, and using RAM that the primary CPU's code wishes
+ * to use. Implementing such co-ordination would be essentially impossible.
+ */
 void machine_restart(char *cmd)
 {
-       machine_shutdown();
+       smp_send_stop();
 
        arm_pm_restart(reboot_mode, cmd);
 
@@ -343,7 +375,8 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start,
        clear_ptrace_hw_breakpoint(p);
 
        if (clone_flags & CLONE_SETTLS)
-               thread->tp_value = childregs->ARM_r3;
+               thread->tp_value[0] = childregs->ARM_r3;
+       thread->tp_value[1] = get_tpuser();
 
        thread_notify(THREAD_NOTIFY_COPY, thread);
 
@@ -411,7 +444,6 @@ static struct vm_area_struct gate_vma = {
        .vm_start       = 0xffff0000,
        .vm_end         = 0xffff0000 + PAGE_SIZE,
        .vm_flags       = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC,
-       .vm_mm          = &init_mm,
 };
 
 static int __init gate_vma_init(void)